Gunite Installation Procedures

Gunite Installation Procedures


J.T. THORPE & SON, INC.

Established 1906Specification No.:JTT-IP-106 Rev. 0

ENGINEERS AND CONTRACTORS JT Thorpe Job No.:60895

Jacobs Engineering / Chevron Refinery SLC

SRU TAIL GAS UNIT

(BFM Job No. 2169)

PROCEDURE FOR HANDLING, MIXING & INSTALLING RESCO’S PROGUN 26-LI REFRACTORY MATERIAL (GUNITE) IN STEERHORN ANCHORS

Specification No. JTT-IP-106 Rev. 0

August 10, 2005

REV / DATE / BY / CHK / APPROVAL /

DESCRIPTION

0 / 10-Aug-05 / KIJ /
For Approval
DISTRIBUTION / A / B / C / 0 / 1 / 2 / 3 / 4 / 5 / 6 / 7 / 8 / 9 / 10 / 11
BFM
1.0 SCOPE / OBJECTIVE

1.1This procedure defines the specific materials, equipment, and application techniques for a dry-gunned refractory material in 1½” & 2” thick single component lining in steerhorn anchors for the SRU Tail Gas Unit for the Chevron Refinery in Salt Lake City, Utah.

1.2This procedure is to be used in conjunction with the customer specifications. However, in case of conflict between this procedure and the customer specifications, the document with the more stringent requirements shall govern.

2.0 MATERIALS & STORAGE

2.1Resco’s ProGun 26-LI (castable) shall be the only refractory material referenced in the succeeding sections of this procedure.

2.1.1The Resco ProGun 26-LI material shall be shipped within 1 month of manufacture and shall be installed within 3 months of manufacture, or 4 months of a succeeding qualification test per procedure. Material shall be delivered in pallets of 72 bags at 55lbs/bag per pallet.

2.1.2Pre-shipment/prequalification testing for the material prior to shipment shall be conducted at Resco’s Laboratory in Santa Fe Springs, CA. Details of testing is specified in Section 6.1.1.

2.2The material storage and temperature control requirements are as follows:

2.2.1Refractory material shall be palletized, shrink-wrapped and stacked on double pallets in the designated storage area. If the material is stored outdoors, then the material shall be covered with a waterproof tarp at all times. Essentially, the material shall be stored in a dry place free from excess dampness and away from direct sunlight.

2.2.2Briefly stated, the material will be stored in an area below 85°F.

3.0EQUIPMENT & CLEANING

3.1The following equipment shall be required for the placement of the refractory material:

3.1.1Spiral Anchor Mixer (Gas or Electric) – Horizontal paddle-type mixer with side dumping mechanism. The mixer should have a minimum capacity of 8 ft3.

3.1.2Rotary Gun or Allentown Double Chamber Gun – These are the most reliable guns commonly used in the industry, where continuous feed of water and material at the gunning nozzle is mixed and placed. Uniform mixing water and material is essential for a quality installation.

3.1.3Double Bubble Nozzle & Material Hose sections – ø1½” and ø2” material hose.

3.1.4Sample Panel - Inside dimensions of mold is 12” x 12” x 4” thick. After production sample has properly cured, we will cut it in half and send 1-half to Jenkins Laboratory for testing and the other half will be kept as a spare for possible re-testing.

3.2All equipment shall be thoroughly cleaned of any portland based cement materials prior to the start of the job. Contamination can affect setting and strength of castables.

3.3Ensure the following items are checked or accounted for prior to starting the job.

3.3.1Continuous, consistent potable water supply.

3.3.2Sufficient electrical supply – Power at 440V 3 phase minimum of 40 Amps to for AP-10 is required.

3.3.3Sufficient air supply using a compressor capable of 300cfm as a minimum. Minimum air pressure at the nozzle for ProGun 26-LI should be 65psi for sidewall applications and 100psi for overhead application.

3.4All equipment shall be maintained in good operational condition throughout the duration of the work.

4.0PREPARATION / SET-UP / MIXING

4.1The surface to be lined shall be clean of loose mill scale and other foreign materials, especially during the weldment of anchors. Surface preparation shall be done in compliance to SSPC-SP3 “Power Tool Cleaning”, as a minimum.

4.2In the event that the anchor welding is performed by others, the JTT Superintendent / Engineer and/or Third Party Inspection shall examine the installation to assure that it is sufficient for refractory installation. All anchors shall be tested by striking the welded anchor with a 1-pound hammer at one-foot centers. Any loose anchors caused by this exercise (or if cracked welds exist) shall be removed and replaced. All replaced anchors shall be hammer-tested subsequently.

4.3Structural members, nozzle extensions/sleeves and other items within the limits of the lining, shall be wrapped with 1/8” thick ceramic fiber paper to prevent bonding to the refractory lining.

4.4Where required, all openings and borders shall be closed by means of sealed (waxed) wood shotboards, and shall not be removed or disturbed until the refractory lining has developed its initial set. All forms shall be sealed with form oil or any other waterproofing agent.

4.5Water shall be potable and clean and shall be between 35°F and 75°F, using ice and water coolers if needed.

4.6The temperature of the surface to be lined should be above 40°F and below 90°F. Temperatures shall be monitored using stick and surface thermometers during the placement of the refractory. Should the situation call for it, water soaker hose shall be placed/wrapped around the exterior body of the vessel to cool the steel.

4.7Pre-dampening of the material in the mixer shall be performed prior to loading the gun. The amount of water required for pre-dampening shall be in accordance with manufacturer’s recommendations.

4.8Add the dry material to the mixer. Add 3% by weight 304SS ø0.02” x 1” fiber needles using a needle shaker and add the predamp amount of specified water to the mixer while dry-mixing. Predamp water content for ProGun 26-LI material is 3% or 0.8 quarts for a 55# sack. Mix for 60-90 seconds until material/water/fiber needles is uniformly mixed.

4.9For this product, this material should be gunned as soon as possible, with little aging and slaking time needed.

5.0PLACEMENT / APPLICATION

5.1At this point during the work, the anchors have been approved and welded on the shell of the equipment. All refractory material shall be applied at the proper air pressure to prevent excessive rebound and lamination, to avert loss of binder, and to produce a dense lining.

5.2Once the parameters are set and the material is flowing smoothly, installation shall be done in a manner such that there is little to no down-hand gunning. Every effort shall be made to shoot normal to the surface. Gun each band/panel to full thickness to avoid laminations, starting at the bottom and working upward. The full thickness shall be developed in one band/panel before proceeding to the next band/panel. Vertical joints between bands shall be staggered.

5.3The intent is to try to gunite continuously with little to no cold/construction joints. We will at a minimum have some shotboards and possibly a moving shotboard set every 8-12ft, and will determine its position and use as soon as we get going.

5.4All rebound and loose material shall be removed from the surface of a completed band before proceeding with the next band. No rebound material shall be allowed to accumulate on the completed lining as hydration of the cement has already started. Rebound material shall not be reused and shall be removed from the anchors and shell before refractory placement is to continue onto the next band.

5.5Application by handpacking or troweling of refractory material is permitted in areas where contouring is required or where space limitations do no permit gunning.

5.6The tolerance of the lining thickness shall be -0” to +1/4” or as specified by the customer. Tolerances shall be measured and controlled with depth gauges and shotboards.

5.7When any significantwork stoppage occurs; for example, at the completion of a shift, the refractory lining shall be cutback 90° to the shell with a steel trowel creating a construction joint. This cutback shall be made through the full thickness of the material already applied and made midway between the anchors. When gunning continues, the existing material at the joint shall be sprayed with water.

5.8Protection of the refractory lining from undesired moisture loss during curing shall be done by spraying a curing compound on the surface of the completed portion of the refractory lining. The curing compound shall be water based and applied with a garden sprayer so as to obtain a thin, continuous film. The curing compound shall be applied within 2 hours of the completion of the lining and/or when the surface appears dry to the touch. This is done in order to prevent water evaporation required for proper hydration and to maximize the material properties. It is assumed that the curing compound will be applied for 100% coverage.

6.0TESTING

6.1Prequalification / Preinstallation tests

6.1.1Prequalification/preshipment material testing shall be 3 density, 3 CCS and 2 PLC every 5000 lbs of material. The tests shall be in accordance with the respective ASTM standards.

6.1.2Prequalification/preshipment tests shall be taken at the material manufacturer’s facility and the tests shall be conducted by the manufacturer’s laboratory in Santa Fe Springs, CA.

6.1.3Each nozzleman shall prequalify by shooting a 3ft x 3ft x 3” thick panel prior to start of work, simulating as close as possible the conditions/restrictions of the installation work itself. The panel shall have a removable back to check for voids and laminations. The test shall be acceptable if the backside has no voids or if incomplete unions of refractory are not evident with the anchoring system.

6.1.4If necessary and/or required, we can send out and test the refractory panel at Jenkins Laboratory. However, we feel that this will not be necessary due to the material already being prequalified.

6.2Production tests

6.2.1Production test samples shall be taken and removed from the vessel once per shift. The production test samples shall be prepared using the same refractory material and equipment. These panels shall be tagged in order to identify each test panel by its date, time of application, batch number, and location of work.

6.2.2Sample panels shall be cut, tagged and sent to Jenkins Lab in Houston, Texas for testing. Spare sample shall be stored at JTT Warehouse should a re-test be required.

6.3Curing of Samples

6.3.1Spray curing compound on sample panels. Allow samples to air cure in the sample box for 24 hours at 50-90°F. Cut samples when ready, i.e. after 24 hours.

6.4ACCEPTANCE / REJECTION CRITERIA

6.4.1All test results, if performed, shall comply with the following criteria:

6.4.1.1Minimum for the ProGun 26-LI PC with 3% 1” 304SS fiber needles will have a cold crushing strength (after firing to 1500°F) of 1400psi.

6.4.1.2Maximum allowable permanent linear change for ProGun 26-LI will be -0.5%.

7.0QUALITY CONTROL / ASSURANCE

7.1General hold points, or inspection points, that shall have the JTT Engineer’s and/or Chevron’s authorized Inpector’s approval before proceeding to the next task are as follows:

  • Procedure qualification / Prequalification of nozzleman per 6.1.3,
  • Anchor installation including hammer-testing and buy-off,
  • Shotboard installation,
  • Gunite refractory lining,
  • Forced Thermal Dry-out
  • Final touch-up/repairs (if necessary)

Discrepancies or differences of opinion regarding the preceding list of items shall be resolved between the JTT Project Manager and Jacobs / Chevron Engineer.

7.2Material Batch Log Sheet - A record of the current atmospheric conditions, manufacturer’s batch/pallet number, mix temperature, mixing time and location of batches in the lining shall be recorded during the entire duration of the work. A copy of the Batch Log sheet is included in this procedure.

8.0THERMAL FORCED DRY_OUT

8.1Thermal dry-out schedule shall be as follows, which is in accordance with the material manufacturer’s recommended procedure.

  • Increase from 75°F to 325°F @ 50°F/hr…………………………….…………………5 hrs
  • Hold @ 325°F for 3 hrs………………………………………………………………….3 hrs
  • Ramp @ 75°F/hr to 700°F………………………………………………………………5 hrs
  • Hold @ 700°F for 3 hrs………………………………………………………………….3 hrs
  • Ramp down 100°F/hr to 300°F…………………………..……………………………..4 hrs

TOTAL DRY-OUT DURATION………………………………………...…………………20 hrs

8.2Please see attached Dry-out Schedule Sheet for more specific details.

9.0REPAIRS

9.1Surface defects that warrant repairs are defined below:

9.1.1Any defect over 1” in depth.

9.1.2Any defect whose average diameter and depth are greater than or equal to ½ “.

9.1.3Any defect whose average diameter is equal to or exceeds 1”, and whose depth is equal to or exceeds ¼”.

9.1.4Cracks which are 1/8” (3mm) or greater in width and penetrate more than 50% of the castable thickness shall be repaired. Repairs shall be made by chipping out the unsound refractory and exposing a minimum of one anchor, making a joint between sound refractory that is perpendicular to the base metal, and then gunning, casting, or hand packing the area to be repaired.

9.2Any part of the work which is defective due to the presence of voids, honeycombing, insufficient curing, or construction damage shall be removed to the full thickness of the layer. An area large enough to expose at least 1 anchor shall be tore-out and tapered back to the shell.

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